Cam operated rotary switch using leaf spring and overlying actuator



Oct. 25, 1966 w. M KINLEY TENNANT 3,281,552

CAM O RATED ROTARY SWI H ING LEAF ING AND OVERLYI A ATOR Filed Oct. 12, 1965 2 Sheets-Sheet 1 Oct. 25, 1966 w. M KINLEY TENNANT 3,231,552

CAM O D R0 Y SWITCH USING LEAF 5 AND RLYING ACTUATOR Filed Oct. 12, 1965 2 Sheets-Sheet 2 United States Patent 3,281,552 CAM OPERATED ROTARY SWITCH USING LEAF SPRING AND OVERLYING ACTUATOR William McKinley Tennant, Brighton, Mass, assignor to Ark-Les Switch Corporation, Watertown, Mass, a corporation of Massachusetts Filed Oct. 12, 1965, Ser. No. 495,040 7 Claims. (Cl. 200-63) The present invention relates to an improved multiple terminal rotary switch of the general type in which the control element is movable to a number of different positions for closing any one or more of a substantial number of different circuits or combinations of such circuits.

It is a principal object of the invention to provide an improved multiple terminal rotary switch which is simple and rugged in construction and readily adjustable to a substantial number of operating positions for connecting a number of different circuits or combinations of such circuits.

It is a further object of the invention to provide an improved multiple terminal rotary switch of this general description, in which the circular base and rotary disc cam cover are so contoured and arranged to provide for the substantial and accurate operation of the rotary switch assemblies mounted therein.

It is a further object of the invention to provide a rugged and efiicient multiple terminal rotary switch of this general description employing snap switches which will have a fast and reliable snap action.

The several features of the invention will be readily appreciated from the following description taken in connection with the accompanying drawing in which:

FIG. 1 is a plan view of the rotary switch including the several features of the invention;

FIG. 2 is a view in side elevation of the rotary switch shown in FIG. 1;

FIG. 3 is a bottom plan view of the rotary switch and corresponds to the illustration of FIG. 2 looking from the right;

FIG. 4 is a sectional view taken on a line 44 of FIG. 2 illustrating particularly the switch operating cam surfaces of the rotatably adjustable cam disc which forms the operating element of the switch;

FIG. 5 is a sectional view taken on a line 55 of FIGURE 2 illustrating particularly the arrangement of the actuating spring arms and snap switch arms;

FIG. 6 is a sectional view taken on a line 6-6 of the bottom plan FIG. 3 showing two opposed snap switch units with the actuating spring arms held down and with the associated snap switch arms in a raised open position;

FIG. 7 is a sectional view through the switch similar to FIG. 6, but taken on a line 7-7 of FIG. 3 but with the switch assembly set in the operating position of FIG. 13, showing the two opposed switch units controlled by the relatively shorter actuating spring arms positioned with the actuating arms raise-d and with the associated snap switch arms closed;

FIG. 8 is an exploded perspective view showing the several switch components but Wit-h the cover of the switch removed;

FIG. 9 is a diagrammatic view illustrating different positions of the switch, indicating four successive step positions of the switch from neutral in each direction; and

FIGS. 10 and 11 illustrate a modification of the invention in which a simple switch arm, normally biased away from its terminal is substituted for the snap switch of FIGS. 1 to 9 to be actuated by a switch actuator arm which is pressed by a raised cam surface on the overlying cam disc of the switch assembly;

FIG. 10 being a sectional view corresponding to FIG. 6; and

3,281,552 Patented Oct. 25, 1966 FIG. 11 being a sectional view corresponding to FIG.

FIGS. 12 to 19 inclusive are diagrammatic views illustrating different positions of the switch of which FIGS. 12 to 15 illustrate positions in which the control handle and cam disc have been moved through four successive steps from neutral in a clockwise direction, and FIGS. 16 to 19 inclusive illustrate positions in which the con trol handle and cam disc have been moved through four successive steps from neutral in a counter-clockwise direc tion.

The rotary snap switch shown in the drawing as embodying in a preferred form, the several features of the invention comprises a housing including a circular base member 20 to which is fitted a cover member 22 hav ing tabs 23 which are bent over the edges of the base 20 in locking relation thereto as shown in FIGS. 2 and 3. The base member 20, formed on an insulating material such as plastic, is apertured to receive a central fastening element or rivet 24 which may act as a com mon contact for the switch. As best shown in FIG. 8, the upper face 25 of the base member 20 is formed with two slots 26, 28 intersecting at right angles along lines passing through the axis of the base member 20. Switch contact terminals consisting of round headed rivets 30, 32, 34 and 36 are mounted in the base member 20 adjacent the ends of the intersecting slots 26, 28 and are connected respectively wit-h switch terminal members 38, 40, 42 and 44 attached to the under side of the base member 20. A metallic element 46 having generally the shape of a cross is fitted into the intersecting slots 26, 28 being centrally supported on an annular supporting surface 48 formed on the base member 22 at the intersection of said slots and held firmly engaged therewith by the rivet 24. The four arms of the cross shaped metallic element 46, which may be made of beryllium copper, are formed to provide four leaf spring snap switches 50, 52, 54 and 56, all having contact with the central ground provided by the rivet 24 and a ground terminal member 57 secured thereto, and at their outer ends having contact buttons 58 to be brought into contact respectively with the terminals provided by the round headed rivets 30, 32, 34 and 36. Each leaf spring snap switch is identically formed with two parallel longitudinal cuts forming two outer tension elements 60 and a central compression element 62 which is normally convex upwardly and biases the outer end of the leaf spring snap switch 49 downwardly into engagement with the associated switch contact terminal. It will be understood that each of the snap switches described may be constructed of two separate parts cooperating to produce the desired snap action without departing from the spirit and scope of the invention. Overlying the element 46 in the intersecting slots 26, 28 is a second fiat, metallic, cross-shaped member 66 which is held firmly by the rivet 24. Each of the arms 68, 70, 72 and 74 provided by the member 66 overlie and acts as an actuator for the corresponding spring snap switch provided by the cross-shaped member 46. Each of the actuator arms 68, 70, 72 and 74 is biased upwardly at the outer end and has formed on the under face thereof a nub 76 which engages against the upwardly bowed central compression element 62 of the associated leaf spring snap switch. A downward movement of a said actuator arm acting through the nub 76 and compression element 62 will cause the snap switch to snap upwardly into open position in which the leaf spring snap switch is engaged against the downwardly pressed actuator arm, as shown in FIG. 6. When released, the switch actuat-or arm will move upwardly releasing the pressure of the nub 76 on the compression element 62 of the leaf spring snap switch which snaps downwardly to the contact position illustrated in FIG. 7. Each of said actuator arms 68, 70, 72 and 74 is provided at its outer end with an upward projection 78 which acts as a cam follower surface. As shown in FIGS. 5 and 8 the actuator arms 70 and 72 are longer than the actuator arms 68 and 74.

For actuating the switch a rotary cont-roller 80 is secured to a stem 82 which is rotatably mounted on a bearing element 84 on the cover member 22, and at its inner end is attached to a disc cam 86 which overlies and is rotatable with relation to the actuator arms 68 to 74 inclusive. As best shown in FIGS. 6 and 7, the disc cam 86 is disposed with the inner face thereof engaged against the adjacent top face .25 of the base member 20, and closely adjacent the actuator arms, so that the upward projections 78 of the associated actuator arms engaging against non-recessed portions of said face will cause said arms to be held in a precisely gaged depressed position in which the associated snap switches are held open. For the off position of the switch shown in FIGS. 1, 2, 4, 5 and 6, all four of the actuator arms 68 to 74 inclusive are held down, so that all four snap switches are disengaged as best shown in FIGS. 4 and 6-.

Referring particularly to FIG. 4 and the diagrammatic views 12 to 19 inclusive, the under face of the disc cam 86 is formed with recesses which are arranged for specified angular positions of the controller 80 and disc cam 86 to receive the projections 78 formed on the respective switch arms which are thus permitted to move away from the associated snap switches allowing said switches to close. It will be noted that these recesses are arcuately formed on radii of two different lengths, those arcuate recesses of shorter radius being adapted to receive projections 78 associated with the two shorter actuator arms 68, 72 while those recesses disposed at a greater radial distance from the rotational axis of the disc cam are arranged to receive the projections 78 associated with the long actuator arms 70, 74.

In the embodiment of the invention shown in FIGS. 1 to 9 inclusive, the inner and outer recesses referred to overlap circumferentially and thus merge with one another. For convenience of illustration the two sets of inner and outer recesses are separated from one another in FIG. 4 by a dot-and-dash construction line.

From a consideration of the diagrammatic showing of FIG. 9 taken in connection with FIGS. 12 to 19 inclusive it will be evident that a substantial number of combinations of open and shut snap switches is possible for different angular positions of the controller 88 and disc cam 86 depending upon the arrangement of recesses formed in said cam.

For the position of FIG. 12 in which the controller 80 and cam disc 86 have been turned clockwise, it will be noted that the short switch actuator arm 68 only is released by engagement of its cam follower projection 78 in the recess 90, causing a circuit to be closed through switch contact terminal 30.

For the position of FIG. 13 in which the controller 80 and cam 86 have been moved still further clockwise, both short switch actuator arms 68 and 72 are released by the engagement of their cam follower projections '78 in the recesses 90 and 92 respectively causing circuits to be closed through switch terminals 30* and 34.

For the still further advanced position of FIG. 14 the short actuator arm 72 and the long actuator arm 74 are released by engagement of their cam follower projections 78 in the respective recesses 92 and 94 so that circuits are completed through switch terminals 34 and 36.

For the extreme clockwise position of FIG. 15 both long actuator arms 70' and 74 are released by engagement of their cam follower projections '78 in the respective recesses 96 and 94, closing circuits through the switch terminals 32 and 36.

For the position of FIG. 16 in which the controller and cam disc have been moved counter-clockwise from the neutral position a circuit is closed through switch terminals 30 and 34. For the further counterclockwise position of FIG. 17 a circuit is closed only through switch terminal 30'. In FIG. 18 circuits are closed through switch terminals 30 and 32, and in FIG. 19 switch circuits are closed through switch terminals 32 and 36.

FIGS. 10 and 11 illustrate a modified construction of my multiple terminal rotary switch in which a switch plate is provided having simple switch arms designated at to take the place of the snap switch arms 50, 52, 54 and 56 of FIGS. 1 to 9 inclusive. Each of the switch arms 100 is biased to a raised out-of-contact position along with the overlying actuator arm. In this construction, since the actuator arms must be pressed to engage the switch contact, the abutting face of the disc cam 102 which overlie-s the switch assembly and corresponds to the disc cam 86 of FIGS. 1 to 9, is radially slotted at 104 to receive the respective actuator arms 68, 70, 72 and 74, and is formed with a peripheral recess 106 in which are received the upwardly biased cam follower surfaces 78 of the respective actuator arms for the out-of-contact position of the respective switches. The actuator arms and associated switch arms 100 are selectively moved to close circuits through any of said terminals 30, 32, 34 or 36 by means of raised cam surfaces which correspond exactly in position and in contour to the recess 90, 92, 94 and 96 respectively, of the embodiment illustrated in FIGS. 1 to 9 and 12 to 19 inclusive, and operate in the positions of the rotary multiple pole switch shown in FIGS. 11 to 19 to close and open the same circuits. In FIG. 10", for example, which corresponds to FIG. 6- the actuator arm 70 rides in the recess I106 permitting the switch arm to stand in open position. In FIG. 11 which corresponds to FIG. 7, the actuator arm 68 rides on the raised cam surface 110 causing the associated switch arm 100 to be engaged with the contact terminal 30.

It will be understood that applicant is not limited to the particular arrangement of the switch operators and associated cam operating disc shown, and that changes may be made within the scope of the invention in accordance with the requirements of the electrical circuits to be controlled thereby, and that applicant is not limitcd to the particular arrangement shown.

The invention having been described what is claimed is:

1. A multiple terminal rotary switch having, in combination, a base support comprising a circular disc of electrically non-conducting material having a common terminal centrally located on the rotational axis of said switch, and a plurality of individual switch terminals spaced radially outwardly from said centrally located common terminal, switch contact arms supported on said disc extending outwardly from said common terminal overlying each of said. individual switch terminals, each shiftable between contact and out-of-contact positions and each said contact arm having a bias to one of said positions, a switch actuator arm overlying each of said switch contact arms arranged when pressed. to engage and to press the underlying switch arm to the alternate position against said bias, and a disc cam overlying said switch actuator arms rotatably adjustable about said central switch terminal as an axis and providing on the under face thereof cam surfaces for selectively pressing and releasing said switch actuators to close and open said respective switch arms.

2. A rotary multiple terminal switch according to claim 1 in which the adjacent face surfaces of said base and disc cam are engaged to provide precisely gaged positions of said cam surface engaged switch actuator arms, and are relatively grooved. radially to receive said switch actuator and switch contact arms.

3. A rotary multiple terminal switch according to claim 2, in which said switch actuator arms are formed with cam follower surfaces disposed at difierent radial distances from said centrally located common terminal, and cam surfaces are disposed on the under side of said. disc cam at radial distances from the rotational axis of said disc cam selected to engage only those cam follower surfaces disposed at the same radial distance from said axis.

4. A rotary multiple terminal switch having, in combination, a circular disc of electrically non-conducting material, having a face thereof formed with a plurality of radial slots, a common terminal centrally disposed in said disc, individual switch terminals disposed outwardly in said several slots, an electrical conductor plate attached to said common terminal having switch contact arms lying in said slots, each shiftable between contact and out-of-contact positions with a said individual switch terminal and biased. to one of said positions, an actuator plate overlying said conductor plate having switch actuator arms overlying said switch contact arms in said slots, movable to shift the associated switch arm to the alternate position against said bias, and a disc cam overlying said switch actuator arms rotatably adjustable about said central switch terminal as an axis and providing on the under face thereof cam surfaces for selectively pressing and releasing said switch actuators to close and open said respective switches.

5. A rotary multiple terminal switch according to claim 4 in which each said switch contact arm is biased to an out-of-contact position with respect to the respective individual switch terminal, and the overlying actuator arm is cam pressed to press the underlying switch contact arm to the contact position.

6. A rotary multiple terminal switch according to claim 4 in which each said individual switch arm is a self-returning snap switch having a 'bias to the closed contact engaging position, and the upwardly biased overlying actuator arm acts when pressed to shift the underlying snap switch to the out-of-contact position.

7. A rotary multiple terminal switch according to claim 6 in which each snap switch arm is formed with tension and compression areas balanced to bias said snap switch against the associated contact terminal, and each snap switch actuator arm has a bias away from said underlying snap switch arm and a contact surface rendered operative by a downward. press movement of the switch actuator arm to engage and snap said snap switch arm open.

No references cited.

ROBERT K. SCHAEFER, Primary Examiner. 

1. A MULTIPLE TERMINAL ROTARY SWITCH HAVING, IN COMBINATION, A BASE SUPPORT COMPRISING A CIRCULAR DISC OF ELECTRICALLLY NON-CONDUCTING MATERIAL HAVING A COMMOM TERMINAL CENTRALLY LOCATED ON THE ROTATIONAL AXIS OF SAID SWITCH, AND A PLURALITY OF INDIVIDUAL SWITCH TERMINALS SPACED RADIALLY OUTWARDLY FROM SAID CENTRALLY LOCATED COMMON TERMINAL, SWITCH CONTACT ARMS SUPPORTED ON SAID DISC EXTENDING OUTWAEDLY FROM SAID COMMON TERMINAL OVERLYING EACH OF INDIVIDUAL SWITCH TERMINALS, EACH SHIFTABLE BETWEEN CONTACT AND OUT-OF-CONTACT POSITIONS AND EACH SAID CONTACT ARM HAVING A BIAS TO ONE OF SAID POSITION, A SWITCH ACTUATOR ARM OVERLYING EACH OF SAID SWITCH CONTACT ARMS ARRANGED WHEN PRESSED TO ENGAGE AND TO PRESS THE UNDERLYING SWITCH ARM TO THE ALTERNATE POSITION AGAINST SAID BIAS, AND A DISC CAM OVERLYING SAID SWITCH ACTUATOR ARMS ROTATABLY ADJUSTABLE ABOUT SAID CENTRAL SWITCH TERMINAL AS AN AXIS AND PROVIDING ON THE UNDER FACE THEREOF CAM SURFACES FOR SELECTIVELY PRESSING AND RELEASING SAID SWITCH ACTUATORS TO CLOSE AND OPEN SAID RESPECTIVE SWITCH ARMS. 